"The SSL connection could not be established" when publishing despite docker login success

[QuantumToasted]

I am attempting to publish my images to a local (LAN, not same device) registry during build via the following publish command:

dotnet publish --os linux --arch x64 -c Release /t:PublishContainer -p:ContainerImageName=linus -p:ContainerRegistry=portainer.local:32768

However, the following error occurs during building (full build output below):

Output

MSBuild version 17.4.1+9a89d02ff for .NET
  Determining projects to restore...
  Restored D:\Code\Linus\Linus.csproj (in 239 ms).
  Linus -> D:\Code\Linus\bin\Release\net7.0\linux-x64\Linus.dll
  Linus -> D:\Code\Linus\bin\Release\net7.0\linux-x64\publish\
  Building image 'linus' with tags 1.0.0 on top of base image mcr.microsoft.com/dotnet/runtime:7.0
  Uploading layer sha256:bb263680fed18eecdc67f885094df6f589bafc19004839d7fdf141df236a61aa to portainer.local
  Uploading layer sha256:dff5dc947f3862f82b1f73d4ecbd58c35db35a33631d54604377e4616759b6e9 to portainer.local
  Uploading layer sha256:753f39de0335d8570d9f310cab6547650ac744d62d1e5cbd6e716a1b9e8191c4 to portainer.local
  Uploading layer sha256:c671073c7a89f080aefc598baca97a4b232d1f597738eae7888033638a8ee31e to portainer.local
  Uploading layer sha256:ed8da48a765e595a4492b50b66824970421bb768d7744a38ab9af815fc3ca1f1 to portainer.local
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error : Failed to push to the output registry: System.AggregateException: One or more erro
rs occurred. (The SSL connection could not be established, see inner exception.) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :  ---> System.Net.Http.HttpRequestException: The SSL connection could not be establ
ished, see inner exception. [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :  ---> System.Security.Authentication.AuthenticationException: Cannot determine the
 frame size or a corrupted frame was received. [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Security.SslStream.GetFrameSize(ReadOnlySpan`1 buffer) [D:\Code\L
inus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Security.SslStream.EnsureFullTlsFrameAsync[TIOAdapter](Cancellati
onToken cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Runtime.CompilerServices.PoolingAsyncValueTaskMethodBuilder`1.StateMa
chineBox`1.System.Threading.Tasks.Sources.IValueTaskSource<TResult>.GetResult(Int16 token) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Security.SslStream.ReceiveBlobAsync[TIOAdapter](CancellationToken
 cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Security.SslStream.ForceAuthenticationAsync[TIOAdapter](Boolean r
eceiveFirst, Byte[] reAuthenticationData, CancellationToken cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Http.ConnectHelper.EstablishSslConnectionAsync(SslClientAuthentic
ationOptions sslOptions, HttpRequestMessage request, Boolean async, Stream stream, CancellationToken cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    --- End of inner exception stack trace --- [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Http.ConnectHelper.EstablishSslConnectionAsync(SslClientAuthentic
ationOptions sslOptions, HttpRequestMessage request, Boolean async, Stream stream, CancellationToken cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request,
Boolean async, CancellationToken cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMe
ssage request, Boolean async, CancellationToken cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Http.HttpConnectionPool.AddHttp11ConnectionAsync(QueueItem queueI
tem) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancel
lationAsync(CancellationToken cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Http.HttpConnectionPool.HttpConnectionWaiter`1.WaitForConnectionA
sync(Boolean async, CancellationToken requestCancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(Htt
pRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolea
n async, CancellationToken cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at Microsoft.NET.Build.Containers.AuthHandshakeMessageHandler.SendAsync(HttpReq
uestMessage request, CancellationToken cancellationToken) in D:\a\_work\1\s\Microsoft.NET.Build.Containers\AuthHandshakeMessageHandler.cs:line 173 [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Net.Http.HttpClient.<SendAsync>g__Core|83_0(HttpRequestMessage reques
t, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at Microsoft.NET.Build.Containers.Registry.BlobAlreadyUploaded(String name, Str
ing digest, HttpClient client) in D:\a\_work\1\s\Microsoft.NET.Build.Containers\Registry.cs:line 381 [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at Microsoft.NET.Build.Containers.Registry.<>c__DisplayClass40_0.<<Push>b__0>d.
MoveNext() in D:\a\_work\1\s\Microsoft.NET.Build.Containers\Registry.cs:line 431 [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error : --- End of stack trace from previous location --- [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at Microsoft.NET.Build.Containers.Registry.Push(Image x, String name, String ta
g, String baseName, Action`1 logProgressMessage) in D:\a\_work\1\s\Microsoft.NET.Build.Containers\Registry.cs:line 460 [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    --- End of inner exception stack trace --- [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledEx
ceptions) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToke
n cancellationToken) [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at System.Threading.Tasks.Task.Wait() [D:\Code\Linus\Linus.csproj]
C:\Users\omitted\.nuget\packages\microsoft.net.build.containers\0.3.2\build\Microsoft.NET.Build.Containers.targets(114,9): error :    at Microsoft.NET.Build.Containers.Tasks.CreateNewImage.Execute() in D:\a\_work\
1\s\Microsoft.NET.Build.Containers\CreateNewImage.cs:line 149 [D:\Code\Linus\Linus.csproj]

Logging into this registry via docker login on the same machine works fine, and does not change the output whether it's run before or after the failed publish. I did have to add it as an insecure registry. (However, I don't have any local images to try pushing to see if it's an issue with the registry, sorry 😢)

Is this an issue with this tool, the registry, or something else? If it perhaps could be the cause, the same local domain (portainer.local) happens to have a self-signed cert for the portainer container itself.

[baronfel]

@QuantumToasted I think this is because we have an assumption that any registry not explicitly on localhost requires TLS - this method enforces this invariant everywhere in our codebase. It seems that for this case this invariant it's true. I expect that setting up and trusting a TLS cert for this portainer instance is out of the question? If so, we should have some kind of way to signal that the registry doesn't require TLS.

[QuantumToasted]

It seems that for this case this invariant it's true. I expect that setting up and trusting a TLS cert for this portainer instance is out of the question?

Not necessarily? My Portainer instance (or specifically, the registry) is intended to be local-only and not accessible outside of the LAN - my personal workflow was doing development on my desktop PC, and then docker build/docker pushing everything to my private registry hosted on Portainer, so I didn't have to pay for or utilize public registries. As such, I didn't really see a reason to require TLS in this case as I would not be communicating with the "outside" to push images to the registry.

However I will concede I am a total newbie when it comes to Docker and other containerization systems, as far as "best practices" go - I might just be doing something totally backwards, explaining why I am having this issue in the first place? If it would make more sense for me, a single developer, to make my workflow conform to a "standard" that most people follow, than to suggest a tool change its functionality to conform to my weird workflow, then that's fine as well.

[wazzamatazz]

Personally, I'd like to have an option of pushing to non-localhost non-TLS registries. I appreciate that it's absolutely not good practice in any sort of professional environment but if I'm just playing around at home and want to push to a registry on a local Raspberry PI I think that should be possible without having to configure TLS, especially because I can configure Docker Desktop to allow that at my own risk.

[giammin]

i'm experiencing the same behavior trying to publish an image to a docker engine running inside wsl2.

[ripebananas]

Bump. I have a similar The SSL connection could not be established error when trying to pull the base image (i.e. the ContainerBaseImage in the csproj file) from a non-TLS local registry. Would be nice to have a similar setting to docker's insecure-registries option.

[mdsitton]

I am also hitting this as well, having this as an option is absolutely needed.

[mdsitton]

Additionally self-signed certificates do not work just as confirmation

Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013: Failed to push to the output registry: System.Net.Http.HttpRequestException: The SSL connection could not be established, see inner exception. [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:  ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid because of errors in the certificate chain: UntrustedRoot [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Security.SslStream.SendAuthResetSignal(ProtocolToken message, ExceptionDispatchInfo exception) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Security.SslStream.CompleteHandshake(SslAuthenticationOptions sslAuthenticationOptions) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Security.SslStream.ForceAuthenticationAsync[TIOAdapter](Boolean receiveFirst, Byte[] reAuthenticationData, CancellationToken cancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Http.ConnectHelper.EstablishSslConnectionAsync(SslClientAuthenticationOptions sslOptions, HttpRequestMessage request, Boolean async, Stream stream, CancellationToken cancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    --- End of inner exception stack trace --- [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Http.ConnectHelper.EstablishSslConnectionAsync(SslClientAuthenticationOptions sslOptions, HttpRequestMessage request, Boolean async, Stream stream, CancellationToken cancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Http.HttpConnectionPool.AddHttp11ConnectionAsync(QueueItem queueItem) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellationAsync(CancellationToken cancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Http.HttpConnectionPool.HttpConnectionWaiter`1.WaitForConnectionAsync(Boolean async, CancellationToken requestCancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at Microsoft.NET.Build.Containers.AuthHandshakeMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) in /_/src/Containers/Microsoft.NET.Build.Containers/AuthHandshakeMessageHandler.cs:line 175 [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at System.Net.Http.HttpClient.<SendAsync>g__Core|83_0(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken) [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at Microsoft.NET.Build.Containers.Registry.BlobAlreadyUploadedAsync(String repository, String digest, HttpClient client, CancellationToken cancellationToken) in /_/src/Containers/Microsoft.NET.Build.Containers/Registry.cs:line 497 [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at Microsoft.NET.Build.Containers.Registry.<>c__DisplayClass51_0.<<PushAsync>b__0>d.MoveNext() in /_/src/Containers/Microsoft.NET.Build.Containers/Registry.cs:line 546 [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013: --- End of stack trace from previous location --- [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at Microsoft.NET.Build.Containers.Registry.PushAsync(BuiltImage builtImage, ImageReference source, ImageReference destination, Action`1 logProgressMessage, CancellationToken cancellationToken) in /_/src/Containers/Microsoft.NET.Build.Containers/Registry.cs:line 575 [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: /home/coda/.nuget/packages/microsoft.net.build.containers/7.0.305/build/Microsoft.NET.Build.Containers.targets(195,5): error CONTAINER1013:    at Microsoft.NET.Build.Containers.Tasks.CreateNewImage.ExecuteAsync(CancellationToken cancellationToken) in /_/src/Containers/Microsoft.NET.Build.Containers/Tasks/CreateNewImage.cs:line 127 [/home/coda/actions-runner/_work/analytics-server/analytics-server/ApiServer/ApiServer.csproj]
Error: Process completed with exit code 1.

[mdsitton]

@baronfel Any thoughts on at least implementing a way to have self-signed certs for this?

[baronfel]

@tmds you have some background here - you mentioned that it may be difficult to trust self-signed certs on Linux. do you have any docs that might clarify the situation?

[tmds]

you have some background here - you mentioned that it may be difficult to trust self-signed certs on Linux. do you have any docs that might clarify the situation?

If I recall correctly, adding a self-signed cert to the system certificate store on Fedora does not cause .NET applications to trust an HTTPS server using that certificate.

I did have to add it as an insecure registry.

Both podman and docker allow to configure certain registries as insecure. podman allows to also configure it on a per-command basis using the --tls-verify=false flag.

The SDK could pick up such a configuration setting through an environment variable, for example: SDK_CONTAINER_INSECURE_REGISTRIES which can be set by the user to a semi-colon separated list of registry names.

[rido-min]

same issue using k3d registry

[baronfel]

It appears that the .NET Runtime respects some OpenSSL certificate store overrides that use environment variables: dotnet/runtime#23666 (comment)

Would this be acceptable here?

[Devqon]

We also host a private docker registry inside our private network without TLS. In my eyes it would be logical that the dotnet publish command should respect the insecure-registries option from the docker daemon.

As a workaround we now forward the port on our dev-machines and (self-hosted) build agents to the registry's ip address to make use (misuse?) of the localhost exception from this TLS rule:

netsh interface portproxy add v4tov4 listenport=$RegistryPort listenaddress=127.0.0.1 connectaddress=$DockerRegistryIp connectport=$RegistryPort